Certain websites have annoying formatting options. I know how to block sections of specific webpages using an addon available for firefox. What I'm looking for, is some way to create edits in how a page displays and save them that way. For example, say a website has a setup with three columns. The right column is a menu, the middle is content, and the right is advertising, help links, and such.

I've already eliminated the annoying advertising and other elements I don't want to display at all. Having done that, there is some unused screen space that I'd like to utilize. I can edit the page view in Inspector so that the content section is wider and fills the space, but it won't stay that way. Basically, I want to keep the dynamic content but apply my own view edits. Is there any way to accomplish this?